If you’ve been paying attention to the headlines today, you’ve probably noticed a lot of coverage of Windows Phone apps. Instagram’s the big one, drawing most of the crowd, but it’s just one of many apps joining the rest at the Windows Phone Store. We’re not the only ones who have been noticing the platform’s app selection really begin to mature, and in a recent interview Microsoft’s Todd Brix asserts that WP8 has finally gotten to the point where it enjoys a critical mass of popular apps, marking Windows Phone’s arrival as a smartphone heavyweight.

Brix points to the availability of about 85% of the top 25 apps around on Windows Phone as evidence that the app library has really made it, but we’re not sure that quite cuts it.

For instance, it’s great when the platform eventually gets an app, like we just saw with Instagram, but there’s nothing big-league about your users having to wait months and months for its release.

Or look at one of the big start-ups getting attention this week: Coin. The companion app you use to configure the versatile card is going to launch for iOS and Android, and all Windows Phone users get is a promise that devs will “keep track of demand” and “consider this for the future.” That doesn’t sound like how we should be discussing a platform that’s reached “critical mass” with its app selection.

A critical mass is self-sustaining. It would mean that WP8 is big enough now that Microsoft doesn’t have to try to woo devs over to the platform.

Not to discount Windows Phone’s growth – each year, we see it become a more and more viable platform for smartphone users – but even with the gains it’s made with its app library, it probably still has a long way to go.